Saw Diamond

i cant find ANY!!!! DIAMOND IN MINE CRAFT!!!!!! HELP!!!!!?

grr i have a year of expierience.. in each of the worlds i have made i got 30 diamonds or so. ON my best world i have never been to the nether or even saw diamond.HELP?!
by the way made a new server be the first to visit and make better!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

It's luck mostly. Heres a trick. Go down to 16 y coordinate.dig in a random direction. Just dig for hours. Whenever you encounter dirt/gravel, dig it all out. Then continue on your original path. I find diamonds all the time that way.